基于多时相遥感影像的围填海动态监测与变化分析——以辽宁省部分沿海县市为例

本研究选取2016年天宫二号宽波段成像仪数据，联合1986、1996、2006年Landsat-5的历史遥感影像数据开展辽宁省部分沿海县市围填海变化监测，并分析湿地-围填海的转移关系。结果表明，1986~2016年，辽宁省部分沿海县市围填海面积持续增加，近10 a增加最多，面积为29499.73 hm2。围填海占用滩涂湿地面积各时期比较稳定，占用近海水域面积逐年上升，占用盐沼湿地面积逐年减少，围填海开发活动具有由陆地向近海转移的趋势。不同时期，湿地-围填海的转移关系有较大差异，进一步权衡不同转移类型的生态服务价值损失与经济价值增加的关系，对科学地进行围填海规划与实施具有指导意义。     

Engineering application of membrane bioreactor for wastewater treatment in China: Current state and future prospect

China has been the forerunner of large-scale membrane bioreactor （MBR） application. Since the first large-scale MBR （≥ 10 000 m^3·d^-1） was put into operation in 2006, the engineering implementation of MBR in China has attained tremendous development. This paper outlines the commercial application of MBR since 2006 and provides a variety of engineering statistical data, covering the fields of municipal wastewater, industrial wastewater, and polluted surface water treatment. The total treatment capacity of MBRs reached 1× 10^6 m^3·d^-1 in 2010, and has currently exceeded 4.5 × 10^6 m^3·d^-1 with -75% of which pertaining to municipal wastewater treatment. The anaerobic/anoxic/aerobie-MBR and its derivative processes have been the most popular in the large-scale municipal application, with the process features and typical ranges of parameters also presented in this paper. For the treatment of various types of industrial wastewater, the configurations of the MBR-based processes are delineated with representative engineering cases. In view of the significance of the cost issue, statistics of capital and operating costs are also provided, including cost structure and energy composition. With continuous stimulation from the environmental stress, political propulsion, and market demand in China, the total treatment capacity is expected to reach 7.5 × 10^6 m^3·d^-1 by 2015 and a further expansion of the market is foreseeable in the next five years. However, MBR application is facing several challenges, such as the relatively high energy consumption. Judging MBR features and seeking suitable application areas should be of importance for the long-term development of this technology.     

二溴海因危险性试验研究

为评价二溴海因(简称DBDMH)在使用、储运过程中的危险性,采用75℃热稳定性试验对二溴海因在高热条件下的稳定性进行了研究,采用C600微量热法测试了二溴海因的放热起始温度、分解热,并依据《联合国关于危险货物运输的建议书-试验和标准手册》对其爆炸性进行了筛选,通过固体氧化性试验和家兔皮肤刺激性/腐蚀性试验分别对二溴海因的氧化性和皮肤刺激性进行了测试。结果表明:二溴海因在75℃热稳定性试验过程中没有出现着火或爆炸,未出现自加热迹象,不属于太不稳定不能运输的物质;其分解反应只有一步,起始反应温度大约为157℃,分解热为384.8J/g,不属于爆炸品;二溴海因具有氧化性,根据《联合国关于危险货物运输的建议书-规章范本》其包装级别为Ⅱ级;在家兔皮肤刺激性/腐蚀性试验中未见不可逆损伤,对皮肤具有强刺激性。     

Measurement of metal bioaccessibility in vegetables to improve human exposure assessments: field study of soil–plant–atmosphere transfers in urban areas,South China

The quality of cultivated consumed vegetables in relation to environmental pollution is a crucial issue for urban and peri-urban areas, which host the majority of people at the global scale. In order to evaluate the fate of metals in urban soil–plant–atmosphere systems and their consequences on human exposure, a field study was conducted at two different sites near a waste incinerator (site A) and a highway (site B). Metal concentrations were measured in the soil, settled atmospheric particulate matter (PM) and vegetables. A risk assessment was performed using both total and bioaccessible metal concentrations in vegetables. Total metal concentrations in PM were (mg kg^?1): (site A) 417 Cr, 354 Cu, 931 Zn, 6.3 Cd and 168 Pb; (site B) 145 Cr, 444 Cu, 3289 Zn, 2.9 Cd and 396 Pb. Several total soil Cd and Pb concentrations exceeded China’s Environmental Quality Standards. At both sites, there was significant metal enrichment from the atmosphere to the leafy vegetables (correlation between Pb concentrations in PM and leaves: r = 0.52, p < 0.05) which depended on the plant species. Total Cr, Cd and Pb concentrations in vegetables were therefore above or just under the maximum limit levels for foodstuffs according to Chinese and European Commission regulations. High metal bioaccessibility in the vegetables (60–79 %, with maximum value for Cd) was also observed. The bioaccessible hazard index was only above 1 for site B, due to moderate Pb and Cd pollution from the highway. In contrast, site A was considered as relatively safe for urban agriculture.     

植物铜耐性机理的研究进展

主要从植物根细胞壁积累固定、细胞膜对铜的吸收控制、金属配体的螯合作用、铜在系统液泡的分隔机制及胁迫蛋白的合成5个方面,分别阐述植物对铜分子的耐性机制的研究进展,全面了解了铜在植物中的亚细胞分布、铜在植物根系到地上部分运输过程的转运机制以及植物在铜胁迫下的抗性反应等。并在此基础上提出了存在的问题以及今后研究的重点。     

Utilization of nano/micro-size iron recovered from the fine fraction of automobile shredder residue for phenol degradation in water

Phenol removal by n/m Fe in the presence of H₂O₂ was highly effective. Increasing the amounts of n/m Fe and H₂O₂?increased the phenol removal rate. Phenol removal was decreased with an increase in the concentration of phenol. The natural pH (6.9) of the solution was highly effective for phenol removal. The pseudo-first-order kinetics was best fitted for the degradation of phenol. The study investigates the magnetic separation of Fe from automobile shredder residue (ASR) (<0.25 mm) and its application for phenol degradation in water. The magnetically separated Fe was subjected to an ultrasonically assisted acid treatment, and the degradation of phenol in an aqueous solution using nano/micro-size Fe (n/m Fe) was investigated in an effort to evaluate the possibility of utilizing n/m Fe to remove phenol from wastewater. The prepared n/m Fe was analyzed by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The effects of the dosages of n/mFe, pH, concentration of phenol and amount of H₂O₂ on phenol removal were evaluated. The results confirm that the phenol degradation rate was improved with an increase in the dosages of n/mFe and H₂O₂; however, the rate is reduced when the phenol concentration is higher. The degradation of phenol by n/mFe followed the pseudo-first-order kinetics. The value of the reaction rate constant (k) was increased as the amounts of n/m Fe and H₂O₂ increased. Conversely, the value of k was reduced when the concentration of phenol was increased. The probable mechanism behind the degradation of phenol by n/m Fe is the oxidation of phenol through hydroxyl radicals which are produced during the reaction between H₂O₂ and n/m Fe.     

气藏型地下储气库完整性管理体系及风险识别

为保证气藏型储气库安全运营,保障天然气储配调峰系统的正常运转,对气藏型储气库进行完整性管理及风险识别.明确气藏型地下储气库完整性管理的对象为地面站场系统、储气库井、地质体3大模块,以地质体完整性管理为气藏型储气库完整性管理的特点及难点,并基于管道完整性管理的理念;提出气藏型储气库完整性管理的6步循环:数据采集,单元识别...     

Evaluation of initiation activity of dimethylarsinic acid: Initiation potential of rat hepatocarcinogenesis

There is a dearth of data on the initiation activity of dimethylarsinic acid (DMA (V)), a major metabolite of the ubiquitous environmental and occupational carcinogen and toxicant, arsenic (As). The initiation activity of DMA (V) was investigated on rat hepatocarcinogenesis with liver being a major target organ for As-induced carcinogenicity. A total of 50 rats at 10 weeks old were randomly divided in a nine-week medium-term bioassay into four groups. Groups 1 and 2 received 200 ppm of DMA (V) in drinking water for four weeks while groups 3 and 4 drank only tap water until the sixth week when groups 1 and 3 were given 0.01% 2-acetylaminofluorene (2-AAF) in their diet for two weeks in the promotion stage. All animals were subjected to two-third partial hepatectomy (PH) at the seventh week. Quantitative analysis of glutathione S-transferase placental form (GST-P) positive foci in liver, a pre-neoplastic marker of rat hepatocarcinogenesis, demonstrated higher numbers in group 1 (DMA (V) + 2-AAF) than 3 (2-AAF alone) at foci consisting of two–four cells and 15 or a greater number of cells. The numbers of GST-P positive foci consisting of five–nine cells were significantly higher in group 1 than 3. Foci consisting of 10–14 cells were also higher but not significantly different. The GST-P positive foci were apparently similar in groups 2 and 4. Expression of total GST-P positive foci was significantly higher in group 1 compared to 2, 3 or 4. The proliferating cell nuclear antigen (PCNA) test performed to clarify the apparent trend of GST-P data revealed significantly higher PCNA index in group 1. Data indicate weak initiation potential of DMA (V) and for the first time appear to provide evidence for initiation activity in DMA (V)-induced hepatocarcinogenesis in rats.     

Investigation of As, Mn and Fe fixation inside the aquifer during groundwater exploitation in the experimental system imitated natural conditions

Water-dissolved oxygen was supplied into anaerobic aquifer , which oxidized Fe(II), Mn(II) and trivalent arsenic and changed them into undissolved solid matter through hydrolysis, precipitation, co-precipitation and adsorption processes. The experiment was carried out on the column imitated a bore core of anaerobic aquifer with water phase containing Fe(II), Mn(II), As(III) concentration of 45.12 mg/L, 14.52 mg/L, 219.4 μg/L, respectively and other ions similarly composition in groundwater. After 6 days of air supply, concentration of iron reduced to 0.38 mg/L, manganese to 0.4 mg/L, arsenic to 9.8 μg/L (equivalent 99.16% of iron, 97.25% of manganese and 95.53% of arsenic fixed), and for other ions, the concentration changed almost according to general principles. Ion phosphate and silicate strongly influenced on arsenic removal but supported iron and manganese precipitation from water phase. Based on the experimental results, new model of groundwater exploitation was proposed.     

Impact of consistent boundary layer mixing approaches between NAM and CMAQ

Discrepancies in grid structure, dynamics and physics packages in the offline coupled NWS/NCEP NAM meteorological model with the U.S. Environmental Protection Agency Community Multiscale Air Quality (CMAQ) model can give rise to inconsistencies. This study investigates the use of three vertical mixing schemes to drive chemistry tracers in the National Air Quality Forecast Capability (NAQFC). The three schemes evaluated in this study represent various degrees of coupling to improve the commonality in turbulence parameterization between the meteorological and chemistry models. The methods tested include: (1) using NAM predicted TKE-based planetary boundary height, h, as the prime parameter to derive CMAQ vertical diffusivity; (2) using the NAM mixed layer depth to determine h and then proceeding as in (1); and (3) using NAM predicted vertical diffusivity directly to parameterize turbulence mixing within CMAQ. A two week period with elevated surface O₃ concentrations during the summer 2006 has been selected to test these schemes in a sensitivity study. The study results are verified and evaluated using the EPA AIRNow monitoring network and other ozonesonde data. The third method is preferred a priori as it represents the tightest coupling option studied in this work for turbulent mixing processes between the meteorological and air quality models. It was found to accurately reproduce the upper bounds of turbulent mixing and provide the best agreement between predicted h and ozonesonde observed relative humidity profile inferred h for sites investigated in this study. However, this did not translate into the best agreement in surface O₃ concentrations. Overall verification results during the test period of two weeks in August 2006, did not show superiority of this method over the other 2 methods in all regions of the continental U.S. Further efforts in model improvement for the parameterizations of turbulent mixing and other surface O₃ forecast related processes are warranted.